Bridge to allow using Pyramid's cookie session implementation in Zope2.

1. Clone the repository. E.g.:

   $ cd /path/to/
   $ git clone git@github.com:zopefoundation/zope2.sessioncookie

2. Get zope2.sessioncookie installed on the Python path. E.g.:

   $ cd /path/to/zope2.sessioncookie
   $ /path/to/virtualenv_with_zope2/bin/pip install -e .
   ...

3. Copy / link the zope2.sessioncookie-meta.zcml file into the $INSTANCE_HOME/etc/package-includes of your Zope instance. (You might need to create the directory first.) E.g.:

   $ cd /path/to/zopes_instance
   $ mkdir -p etc/package-includes
   $ cd etc/package-includes
   $ ln -s \
       /path/to/zope2.sessioncookie/zope2.sessioncookie-meta.zcml .

4. Generate a 32-byte, hexlified secret:

   $ /path/to/virtualenv_with_zope2/bin/print_secret
   DEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEF

5. Edit the site.zcml for your instance. E.g.:

   $ cd /path/to/zopes_instance
   $ vim etc/site.zcml

   Add an XML namespace declaration at the top, e.g.:

   xmlns:sc="https://github.com/zopefoundation/zope2.sessioncookie"

   Add a stanza near the end, configuring the cookie session. E.g.:

   <sc:sessioncookie
    secret="DEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEF"
    secure="False"
    encrypt="True"/>

6. Run the installation script, which disables the standard session manager and adds the new hook. E.g.:

   $ bin/zopectl run \
       /path/to/zope2.sessioncookie/zope2/sessioncookie/scripts/install.py

7. (Re)start your Zope instance. Test methods which set session variables, and inspect request / response cookies to see that _ZopeId is no longer being set, while session is set (with encrypted, base64-encoded data).